Data busses in a computing platform generally produce electromagnetic radiation that can be a main source of radio frequency interference (RFI) with wireless radio reception in mobile computing platforms such as tablets, smartphones, and portable personal computers. For example, a portable computing platform may have at least three radio antennas, with one or more in its base. In addition, such platforms typically support five or more radio bands, e.g., Wi-Fi (802.11a/b/g/n), Bluetooth technology, and various different cellular standards such as LTE and WiMax, among others.
One RFI mitigation approach uses an active data coding technique referred to as spectral line coding, which mitigates bus noise generated at desired frequency bands by modifying the binary signal data before it is transmitted on the bus. Another RFI mitigation approach, referred to as assisted baseband cancellation, mitigates bus noise by introducing a signal at the radio receiver baseband level that is intended to cancel the noise generated by the bus. Both techniques rely on being able to accurately determine the magnitude and phase of the RFI caused by the digital signals at one or more frequencies.